Organic light emitting display

ABSTRACT

Disclosed is an organic light emitting display which has a scan driver to supply scan signals to a plurality of scan lines, a data driver to supply data signal to output lines, with a demultiplexer on each output line to supply the data signal to a plurality of data lines is disclosed. The display also has a pixel portion comprising pixels connected to the scan lines, the data lines, and pixel power source lines. There is also a power source line placed between the pixel portion and the data driver to supply first power to the pixel power source lines, and a parasitic capacitor formed on each data line to charge voltage corresponding to the data signal. With this configuration, the number of output lines provided in a data driver is decreased, and an image is displayed with uniform brightness.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.2004-80624, filed on Oct. 8, 2004, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to an organic light emitting display, andmore particularly, to an organic light emitting display in which thenumber of output lines provided in a data driver is decreased, and animage is displayed with uniform brightness.

2. Discussion of Related Art

Recently, various flat panel displays have been developed, which replacea cathode ray tube (CRT) in a display because the CRT is relativelyheavy and bulky. The flat panel display can be one of varioustechnologies, including a liquid crystal display (LCD), a field emissiondisplay (FED), a plasma display panel (PDP), and an organic lightemitting display (LED).

An organic light emitting display comprises a plurality of organic lightemitting diodes, where each organic light emitting diode emits light byelectron-hole recombination. Such an organic light emitting display hasadvantages that include relatively fast response time and that powerconsumption is relatively low. Generally, the organic light emittingdisplay employs a thin film transistor (TFT) for each pixel toselectively supply current to an organic light emitting diode accordingto a data signal. When current is supplied, the organic light emittingdiode emits light.

FIG. 1 (PRIOR ART) illustrates a conventional organic light emittingdisplay.

Referring to FIG. 1, a conventional organic light emitting displaycomprises a pixel portion 30 comprising a plurality of pixels 40 formednear intersections of scan lines S1 through Sn and data lines D1 throughDm. The conventional organic light emitting display also has a scandriver 10 to drive the scan lines S1 through Sn, a data driver 20 todrive the data driver D1 through Dm; and a timing controller 50 tocontrol the scan driver 10 and the data driver 20.

The scan driver 10 generates a scan signal in response to a scan controlsignal SCS transmitted from the timing controller 50, and supplies thescan signals to the scan lines S1 through Sn in sequence. Further, thescan driver 10 generates an emission control signal in response to thescan control signal SCS, and supplies the emission control signals toemission control lines El through En in sequence.

The data driver 20 generates a data signal in response to a data controlsignal DCS transmitted from the timing controller 50, and supplies thedata signals to the data lines D1 through Dm. The data driver 20 alsosupplies the data signal corresponding to one horizontal line perhorizontal period to the data lines D1 through Dm.

The timing controller 50 generates the data control signals DCS and thescan control signals SCS in response to external synchronizationsignals. The data control signal DCS is transmitted to the data driver20, and the scan control signal SCS is transmitted to the scan driver10. Further, the timing controller 50 rearranges external data andsupplies it to the data driver 20.

The pixel portion 30 receives external first power VDD and externalsecond power VSS. Here, the first power VDD and the second power VSS aresupplied to each pixel 40. Each pixel 40 receives the data signal anddisplays an image corresponding to the data signal. Further, theemission time of the pixels 40 is controlled in correspondence with theemission control signal.

In the conventional organic light emitting display, the respectivepixels 40 are placed near the intersections of the scan lines S1 throughSn and the data lines D1 through Dm. The data driver 20 comprises moutput lines to supply the data signals to m data lines D1 through Dm.That is, the data driver 20 of the conventional organic light emittingdisplay should have the same number of output lines as the number of thedata lines D1 through Dm. Therefore, the data driver 20 comprises aplurality of data integrated circuits to have m output lines, therebyresulting in a problem of increased production cost. Particularly, asthe resolution and the size of the pixel portion 30 increase, the numberof output lines of the data driver 20 increases. Thus, the productioncost of the organic light emitting display is increased.

SUMMARY OF CERTAIN INVENTIVE EMBODIMENTS

Accordingly, it is an aspect of the present invention to provide anorganic light emitting display, in which the number of output linesprovided in a data driver is decreased and the image is displayed withuniform brightness.

One embodiment includes an organic light emitting display including ascan driver configured to supply scan signals to a plurality of scanlines, a data driver configured to supply data signals to a plurality ofoutput lines, a plurality of demultiplexers, each configured toselectively supply the data signals from a single output line to aplurality of data lines, a pixel portion including a plurality ofpixels, the pixel portion being connected to the scan lines, the datalines, and pixel power source lines, an auxiliary power source lineplaced between the pixel portion and the data driver to supply a firstpower to the pixel power source lines, and a plurality of parasiticcapacitors each formed from a single data line and the auxiliary powersource line in an area where the single data line and the auxiliarypower source line overlap. The parasitic capacitors are each configuredto store charge corresponding to the data signal on the correspondingdata line and at least two of the plurality of parasitic capacitors areformed from the auxiliary power source line and at least two data lineshaving different widths.

Another embodiment includes an organic light emitting display includinga scan driver configured to supply scan signals to a plurality of scanlines, a data driver configured to supply the data signals to aplurality of output lines, a plurality of demultiplexers, eachconfigured to selectively supply data signals from a single output lineto a plurality of data lines, a pixel portion including a plurality ofpixels, the pixel portion being connected to the scan lines, the datalines, and pixel power source lines, an auxiliary power source lineplaced between the pixel portion and the data driver to supply a firstpower to the pixel power source lines. The auxiliary power source linehas a center portion wider than an edge portion, and a plurality ofparasitic capacitors each formed from a single data line and the powersource line in an area where the single data line and the power sourceline overlap. The parasitic capacitors are each configured to storecharge corresponding to the data signal on the corresponding data line.

Another embodiment includes an organic light emitting display includinga scan driver configured to supply scan signals to a plurality of scanlines, a data driver configured to supply the data signals to aplurality of output lines, a plurality of demultiplexers, eachconfigured to selectively supply data signals from a single output lineto a plurality of data lines, a pixel portion including a plurality ofpixels, the pixel portion being connected to the scan lines, the datalines, and pixel power source lines, an auxiliary power source lineplaced between the pixel portion and the data driver to supply a firstpower to the pixel power source lines, and a plurality of parasiticcapacitors each formed from a single data line and the auxiliary powersource line in an area where the single data line and the auxiliarypower source line overlap. The parasitic capacitors are each configuredto store charge corresponding to the data signal on the correspondingdata line and at least two of the plurality of parasitic capacitors areformed from the auxiliary power source line and bending portions of atleast two data lines.

Another embodiment includes an organic light emitting display includinga scan driver configured to supply scan signals to a plurality of scanlines, a data driver configured to supply data signals to a plurality ofoutput lines, a plurality of demultiplexers, each configured toselectively supply the data signals from a single output line to aplurality of data lines, a pixel portion including a plurality ofpixels, the pixel portion being connected to the scan lines, the datalines, and pixel power source lines, an auxiliary power source lineplaced between the pixel portion and the data driver to supply a firstpower to the pixel power source lines, and a plurality of parasiticcapacitors each formed from a single data line and the auxiliary powersource line in an area where the single data line and the auxiliarypower source line overlap. The parasitic capacitors are each configuredto store charge corresponding to the data signal on the correspondingdata line and the surface area of the overlapping area of each of theplurality of parasitic capacitors is substantially equal to the surfacearea of the overlapping areas of each of the other parasitic capacitors.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of certain inventive aspectsare discussed with further detailed exemplary embodiments with referenceto the attached drawings in which:

FIG. 1 illustrates a conventional organic light emitting display;

FIG. 2 illustrates an organic light emitting display according to oneinventive embodiment;

FIG. 3 is a circuit diagram of a demultiplexer illustrated in FIG. 2;

FIG. 4 illustrates waveforms of driving signals supplied to a scan line,a data line and the demultiplexer;

FIG. 5 is a circuit diagram of a pixel illustrated in FIG. 2;

FIG. 6 is a circuit diagram illustrating a connection structure betweenthe demultiplexer of FIG. 3 and the pixel of FIG. 5;

FIG. 7 illustrates a layout of the organic light emitting displayaccording to another inventive embodiment;

FIG. 8 is an enlarged view showing an embodiment of “A” shown in FIG. 7;

FIG. 9 is an enlarged view showing an embodiment of “A” shown in FIG. 7;and

FIG. 10 is an enlarged view showing yet another inventive embodiment of“A” shown in FIG. 7.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

Hereinafter, embodiments according to the present invention will bedescribed with reference to the accompanying drawings. As descriptionherein includes the connection of first and second elements, suchdescription contemplates the embodiments where the first and secondelements are connected via a third element. Additionally, like referencenumerals refer to like elements throughout.

FIG. 2 illustrates an organic light emitting display according to oneinventive embodiment.

Referring to FIG. 2, an organic light emitting display according to oneembodiment of the present invention comprises a scan driver 110, a datadriver 120, a pixel portion 130, a timing controller 150, ademultiplexing block 160, a demultiplexer controller 170, and aplurality of data capacitors Cdata.

The pixel portion 130 comprises a plurality of pixels 140 placed nearthe intersections of scan lines S1 through Sn and data lines DL1 throughDLm. Each pixel 140 emits light according to a data signal transmittedthrough the corresponding data line DL.

The scan driver 110 generates a scan signal in response to a scancontrol signal SCS supplied from the timing controller 150, and suppliesthe scan signals to the scan lines S1 through Sn in sequence. Here, thescan driver 110 supplies the scan signal during a predetermined periodin one horizontal period 1H (Refer to FIG. 4).

For example, the one horizontal period 1H according to one embodiment isdivided into a scan period (first period) and a data period (secondperiod). That is, the scan driver 110 supplies the scan signal to thescan lines S during the scan period in the one horizontal period 1H. Onthe other hand, the scan driver 110 does not supply the scan signalduring the data period in the one horizontal period 1H. Further, duringthe data period the scan driver 119 generates the emission controlsignals in response to the scan control signals SCS, and supplies theemission control signals to emission control lines E1 through En insequence.

The data driver 120 generates the data signal in response to a datacontrol signal DCS supplied from the timing controller 150, and suppliesthe data signals to first data lines D1 through Dm/i. Here, the datadriver 120 supplies m/i data signals (where i is a natural number of 2or more) to the first data lines D1 through Dm/i.

For example, the data driver 120 supplies real data signals R, G, B tothe pixel in sequence during the data period in the one horizontalperiod 1H. Here, the real data signals R, G, B are supplied during onlythe data period, so that the timing of supplying the real data signalsR, G, B are not overlapped with that of supplying the scan signal.Further, the data driver 120 supplies a dummy data signal DD during thescan period in the one horizontal period 1H.

The timing controller 150 generates the data control signals DCS and thescan control signals SCS corresponding to external synchronizationsignals. The data control signals DCS generated in the timing controller150 are supplied to the data driver 120, and the scan control signalsSCS generated in the timing controller 150 are supplied to the scandriver 110.

The demultiplexer block 160 comprises m/i demultiplexers 162. In otherwords, the demultiplexer block 160 has the same number of demultiplexers162 as the number of the first data lines D1 through Dm/i. The m/idemultiplexers 162 are connected to the first data lines D1 throughDm/i, respectively. Further, each demultiplexer 162 is connected to isecond data lines DL. Thus, each demultiplexer 162 supplies i datasignals received during each data period to i second data lines DL.

Accordingly, as the data signal received through one first data line Dis supplied to i second data lines DL, the number of output linesprovided in the data driver 120 is decreased by a factor of i. Forinstance, when i is 3, the number of output lines provided in the datadriver 120 is decreased by a factor of 3, and therefore the number ofcorresponding data integrated circuits provided in the data driver 120is also decreased i, thereby reducing production cost of the organiclight emitting display.

The demultiplexer controller 170 supplies i control signals to thedemultiplexers 162 during the data period in the one horizontal period,thereby demultiplexing the data signal into i data signals and supplyingi data signals from the first data line D to i second data lines DL.Here, the demultiplexer controller 170 supplies i control signalssequentially, so that the i control signals do not overlap in time, asshown in FIG. 4. In this embodiment, the demultiplexer controller 170 isseparate from the timing controller 150, but in other embodiments thedemultiplexer controller may be integrated with the timing controller150.

The data capacitor Cdata is provided in every second data line DL.

Here, the data capacitor Cdata temporarily stores the data signalsupplied to the second data line DL, and supplies the stored data signalto the pixel 140. In some embodiments, the data capacitor Cdata is aparasitic capacitor. According to some embodiments, the capacitance ofthe parasitic capacitor is larger than a storage capacitor Cst providedin every pixel 140 (refer to FIG. 5).

FIG. 3 is a circuit diagram of a demultiplexer illustrated in FIG. 2.

For the sake of convenience, let i be 3. Further, let the demultiplexershown in FIG. 3 be connected to the 1^(st) first data line D1.

Referring to FIG. 3, the demultiplexer 162 comprises a first switchingdevice (or transistor) T1, a second switching device T2, and a thirdswitching device T3.

The first switching device T1 is connected between the 1^(st) first dataline D1 and the 1^(st) second data line DL1. Here, the first switchingdevice T1 is turned on when it receives a first control signal CS1 fromthe demultiplexer controller 170, and supplies the data signal from the1^(st) first data line D1 to the 1^(st) second data line DL1. The datasignal supplied to the 1^(st) second data line DL1 is temporarily storedin the first data capacitor Cdata1.

The second switching device T2 is connected between the 1^(st) firstdata line D1 and the 2^(nd) second data line DL2. Here, the secondswitching device T2 is turned-on when it receives a second controlsignal CS2 from the demultiplexer controller 170, and supplies the datasignal from the 1^(st) first data line D1 to the 2^(nd) second data lineDL2. The data signal supplied to the 2^(nd) second data line DL2 istemporarily stored in the second data capacitor Cdata2.

The third switching device T3 is connected between the 1^(st) first dataline D1 and the 3^(rd) second data line DL2. Here, the third switchingdevice T3 is turned on when it receives a third control signal CS3 fromthe demultiplexer controller 170, and supplies the data signal from the1^(st) first data line D1 to the 3^(rd) second data line DL3. The datasignal supplied to the 3^(rd) second data line DL3 is temporarily storedin the third data capacitor Cdata3. With this configuration, operationsof the demultiplexer 162 will be described in association withconfigurations of the pixel 140.

FIG. 5 is a circuit diagram of a pixel illustrated in FIG. 2. Here, thepixel is not limited to the structure shown in FIG. 5. The pixel may,for example, comprise at least one transistor capable of being used as adiode.

Referring to FIG. 5, each pixel 140 according to one embodimentcomprises an organic light emitting diode OLED, and a pixel circuit 142,which is connected to the second data line DL, the scan line Sn, and theemission control line En and is configured to control light emission ofthe organic light emitting diode OLED.

The organic light emitting diode OLED comprises an anode electrodeconnected to the pixel circuit 142, and a cathode electrode connected toa second power source line VSS. The second power source line VSS isapplied with voltage lower than that of a first power source line VDD.For example, ground voltage can be applied to the second power sourceline VSS. The organic light emitting diode OLED emits light depending oncurrent supplied from the pixel circuit 142. For this, the organic lightemitting diode OLED includes fluorescent and/or phosphorescent organicmaterial.

The pixel circuit 142 comprises a storage capacitor C and a sixthtransistor M6 which are connected in series between the first powersource line VDD and the (n-1)^(th) scan line Sn-1. The pixel circuit 142also comprises a second transistor M2 and a fourth transistor M4 whichare connected in series between the first power source line VDD and thedata line DL. A fifth transistor M5 is connected between the organiclight emitting diode OLED and the emission control line En, and a firsttransistor M1 is connected between the fifth transistor M5 and a firstnode N1. Also a third transistor M3 is connected between gate and drainterminals of the first transistor M1. In the embodiment of FIG. 5, thefirst through sixth transistors M1 through M6 are of a p-type metaloxide semiconductor field effect transistor (PMOSFET), but otherembodiments have other types of switching devices. For example, thefirst through sixth transistors M1 through M6 may be of an n-type metaloxide semiconductor field effect transistor (NMOSFET). In the case wherethe first through sixth transistors M1 through M6 are of the NMOSFET,polarity of driving waveforms is reversed as well-known to those skilledin the art.

The first transistor M1 comprises a source terminal connected to thefirst node N1, the drain terminal connected to a source terminal of thefifth transistor M5, and the gate terminal connected to the storagecapacitor C. Further, the first transistor M1 supplies currentcorresponding to voltage charged in the storage capacitor C to theorganic light emitting diode OLED.

The third transistor M3 comprises a drain terminal connected to the gateterminal of the first transistor M1, a source terminal connected to thedrain terminal of the first transistor M1, and a gate terminal connectedto the n^(th) scan line Sn. Further, the third transistor M3 is turnedon when the scan signal is transmitted to the nth scan line Sn, and thusmakes the first transistor M1 be connected like a diode. That is, whenthe third transistor M3 is turned on, the first transistor M1 functionsas a diode.

The second transistor M2 comprises a source terminal connected to thedata line DL, a drain terminal connected to the first node N1, and agate terminal connected to the n^(th) scan line Sn. Further, the secondtransistor M2 is turned on when the scan signal is transmitted to then^(th) scan line Sn, thereby transmitting the data signal from the dataline DL to the first node N1.

The fourth transistor M4 comprises a drain terminal connected to thefirst node N1, a source terminal connected to the first power sourceline VDD, and a gate terminal connected to the emission control line En.Further, the fourth transistor M4 is turned on when the emission controlsignal En is not supplied, thereby electrically connecting the firstpower source line VDD with the first node N1.

The fifth transistor M5 comprises a source terminal connected to thedrain terminal of the first transistor M1, a drain terminal connected tothe organic light emitting diode OLED, and a gate terminal connected tothe emission control line En. Further, the fifth transistor M5 is turnedon when the emission control signal En is not supplied, therebysupplying current from the first transistor M1 to the organic lightemitting diode OLED.

The sixth transistor M6 comprises a source terminal connected to thestorage capacitor C, and drain and gate terminals connected to the(n-1)^(th) scan line Sn-1. Further, the sixth transistor M6 is turned onwhen the scan signal is transmitted to the (n-1)^(th) scan line Sn-1,thereby initializing the storage capacitor C and the gate terminal ofthe first transistor M1.

FIG. 6 is a circuit diagram illustrating an embodiment of a connectionstructure between the demultiplexer of FIG. 3 and the pixel of FIG. 5.Here, one demultiplexer is connected with 3 pixels, one for each of red(R), green (G) and blue (B). i In this embodiment i is 3.

The operations of the demultiplexer 162 and the pixel 140 will bedescribed with reference to FIGS. 4 and 6. First, the scan signal istransmitted to the (n-1)^(th) scan line Sn-1 during the scan period inthe one horizontal period. When the scan signal is transmitted to the(n-1)^(th) scan line Sn-1, each sixth transistor M6 of the pixels 142R,142G and 142B is turned on. According as the sixth transistor M6 isturned on, the storage capacitor C and the gate terminal of the firsttransistor M1 are connected to the (n-1)^(th) scan line Sn-1. That is,when the scan signal is transmitted to the (n-1)^(th) scan line Sn-1,the scan signal is supplied to each storage capacitor C and each gateterminal of the first transistor M1 provided in the pixels 142R, 142Gand 142B, thereby initializing each storage capacitor C and each gateterminal of the first transistor M1. Here, the scan signal SS has avoltage level lower than that of the data signal.

When the scan signal is transmitted to the (n-1)^(th) scan line Sn-1,the second transistor M2 connected to the n^(th) scan line Sn ismaintained being turned off.

Then, the first through third switching devices T1 through T3 are turnedon in sequence by the first through third control signals CS1 throughCS3 transmitted in sequence during the data period. When the firstswitching device T1 is turned on by the first control signal CS1, thedata signal is transmitted from the 1^(st) first data line D1 to the1^(st) second data line DL1. At this time, the first data capacitorCdata1 is charged with voltage corresponding to the data signaltransmitted to the 2^(nd) second data line DL1.

When the second switching device T2 is turned on by the second controlsignal CS2, the data signal is transmitted from the 1^(st) first dataline D1 to the 2^(nd) second data line DL2. At this time, the seconddata capacitor Cdata2 is charged with voltage corresponding to the datasignal transmitted to the 2^(nd) second data line DL2. When the thirdswitching device T3 is turned on by the third control signal CS3, thedata signal is transmitted from the 1^(st) first data line D1 to the3^(rd) second data line DL3. At this time, the third data capacitorCdata3 is charged with voltage corresponding to the data signaltransmitted to the 3^(rd) second data line DL3. Meanwhile, the scansignal SS is not supplied during the data period, so that the datasignal is not supplied to the pixels 142R, 142G and 142B.

Following the data period, the scan signal is transmitted to the n^(th)scan line Sn. When the scan signal is transmitted to the n^(th) scanline Sn, each second transistor M2 and each third transistor M3 of thepixels 142R, 142G and 142B are turned on. According as each secondtransistor M2 and each third transistor M3 of the pixels 142R, 142G and142B are turned on, voltages corresponding to the data signals stored inthe first through third data capacitor Cdata1 through Cdata3 aresupplied to the respective first nodes N1 of the pixels 142R, 142G and142B.

Here, because the voltage applied to the gate terminal of each firsttransistor M1 provided in the pixels 142R, 142G and 142B is initializedby the scan signal transmitted to the (n−1)^(th) scan line Sn-1, i.e.,is set to have a voltage level lower than that of the data signalapplied to the first node N1, the first transistor M1 is turned on.According as the first transistor M1 is turned on, the voltagecorresponding to the data signal applied to the first node N1 issupplied to one terminal of the storage capacitor C via the firsttransistor M1 and the third transistor M3. At this time, each storagecapacitor C provided in the pixels 142R, 142G and 142B is charged withvoltage corresponding to the data signal. Further, the storage capacitorC is additionally charged with voltage corresponding to the thresholdvoltage of the first transistor M1 as well as the voltage correspondingto the data signal. Then, while the emission control signal EMI is notsupplied through the emission control line E, the fourth and fifthtransistors M4 and M5 are turned on, so that current corresponding tothe voltage charged in the storage capacitor C is supplied to theorganic light emitting diode OLED, thereby allowing the organic lightemitting diode OLED to emit light.

Thus, according to one embodiment, the demultiplexer 162 is employed fordemultiplexing the data signals from the first data line D1 to i seconddata lines DL. Further, the data capacitor Cdata is charged with thevoltage corresponding to the data signal during the data period. Duringthe scan period, a data signal dependent voltage is transferred to thestorage capacitor C. According to an embodiment, the scan period forsupplying the scan signal and the data period for supplying the datasignal are not overlapped. This insures that the voltage applied to thegate terminal of the third transistor M3 does not allow the firsttransistor M1 gate voltage to change while the organic light emittingdisplay is displaying an image. Further, the voltages stored in the datacapacitors Cdata are supplied to the pixels at the same time, that is,the data signals are supplied to the pixels at the same time, so thatthe organic light emitting display can display an image with accuratecolor and brightness.

Meanwhile, according to an embodiment of the present invention, the datacapacitors Cdata equivalently formed on the second data line DL shouldbe approximately equal to each other in capacity to display an imagewith accurate color and brightness. In other words, all data capacitorsCdata should be set to have approximately equal capacity so that eachorganic light emitting diode OLED emits the same light as the otherorganic light emitting diodes OLED for the same data signal. Toaccomplish this, according to one embodiment, the organic light emittingdisplay is proposed to have a layout as shown in FIG. 7.

FIG. 7 illustrates a layout of the organic light emitting displayaccording to one embodiment.

Referring to FIG. 7, the organic light emitting display according to oneembodiment has a pixel portion 130 formed on a substrate 300.The pixelportion 130 has a plurality of pixels 140, a plurality of second datalines DL, a plurality of scan lines S, and a plurality of pixel powersource lines VDD. The organic light emitting display also has a firstpower source line 210 and an auxiliary power source line 212 connectedto the pixel power source line VDD, a data driver 120, and ademultiplexer block 160.

According to another embodiment, the organic light emitting displayfurther comprises a scan driver 110, a second power source line 230, anda pad part 200.

The scan driver 110 is disposed in one side of the pixel portion 130 andelectrically connected to a first pad Ps of the pad part 200. The scandriver 110 supplies the scan signals to the scan lines S in sequence forthe scan period in the one horizontal period 1H in response to the scancontrol signal SCS supplied from the first pad Ps.

The data driver 120 is electrically connected to second pads Pd of thepad part 200 and the first data line D. The data driver 120 generates adata signal corresponding to the data control signal DCS and datasupplied from the second pads Pd, and supplies the generated datasignals to the first data lines D. The data driver 120 supplies m/i datasignals to the respective first data liens D for the data period in theone horizontal period 1H. The data driver 120 can be directly formed onthe substrate 300, or embedded as a chip on the substrate 300. Forexample, the data driver 120 can be embedded as a chip on the substrate300 by a chip-on glass method, a wire bonding method, a flip-chipmethod, a beam lead method, or another method.

The first power source line 210 is formed to be adjacent to opposite andtop sides of the pixel portion 130 along the edges of the substrate 300except the pad part 200. Here, the first power source line 210 comprisesopposite ends connected to a third pad Pvdd1 of the pad part 200.Further, the first power source line 210 supplies voltage of the firstpower VDD received through the third pad Pvdd1 to first ends of thepixel power source lines VDD.

The auxiliary power source line 212 is formed to be adjacent to a bottomside of the pixel portion 130. The auxiliary power source line 212comprises opposite ends electrically connected to a fourth pad Pvdd2 ofthe pad part 200. Here, the auxiliary power source line 212 supplies thevoltage of the first power VDD received through the fourth pad Pvdd2 tosecond ends of the pixel power source lines VDD.

The second power source line 230 is formed on the whole area of thepixel portion 130. Here, the second power source line 230 commonlysupplies the voltage of the second power VSS received through a fifthpad Pvss of the pad part 200 to each pixel 140.

The demultiplexer block 160 is placed between the data driver 120 andthe auxiliary power source line 212. The demultiplexer block 160supplies mdata signals received through the first data line D to msecond data lines DL in response to the control signals CS1, CS2, CS3transmitted from a sixth pad Pc of the pad part 200. Further, the datasignals sequentially supplied from the demultiplexer block 160 arestored in the data capacitor Cdata formed on the second data lines DL,and supplied to the pixels 140. Moreover, as the demultiplexer block 160is placed between the data driver 120 and the auxiliary power sourceline 212, the capacitor is formed in a region where the second powersource line DL and the auxiliary power source line 212 overlap. Thisincreases the capacitance of the data capacitor Cdata.

The data capacitors Cdata connected to each second data line DL shouldbe approximately equal to each other in capacitance. Therefore,according to one embodiment, the areas in which the second data lines DLare overlapped with the auxiliary power source lines 212 should beapproximately equal to each other regardless of positions of the seconddata lines DL. As a result the data capacitors Cdata have approximatelyequal capacity, so that each organic light emitting diode OLED emits thesame light as the other organic light emitting diodes OLED for the samedata signal.

FIG. 8 is an enlarged view showing a first embodiment of “A” shown inFIG. 7.

Referring to FIG. 8, the second data lines DL according to oneembodiment various widths so that the areas in which the second datalines DL are overlapped with the auxiliary power source lines 212 areapproximately equal to each other regardless of the positions of thesecond data lines DL.

Further, the length of the demultiplexer block 160 is less than the edgeof the pixel portion 130. Therefore, the second data lines DL1 throughDLm connected to the demultiplexer block 160 are elongated as they gofrom a center portion of the demultiplexer block 160 toward an edgeportion thereof. For example, the second data line DL formed in the edgeportion is twice as long as the second data line DL formed in the centerportion.

Therefore, an overlapping length between the second data lines DL1, DLmformed in the edge portions of the demultiplexer portion 160 and theauxiliary power source line 212 is set to be longer than that betweenthe second data lines DLm/2 (not shown) formed in the center portion andthe auxiliary power source line 212. However, when the second data linesDL1 through DLm are set to have the same width, the capacity of the datacapacitor Cdata equivalently formed on the second data lines DL1 and DLmformed in the edge portions of the auxiliary power source line 212 islarger than that of the data capacitor Cdata equivalently formed on thesecond data line DLm/2 formed in the center portion of the auxiliarypower source line 212, so that an image is displayed with non-uniformbrightness. To prevent the image from being displayed with non-uniformbrightness, according to an embodiment of the present invention, thewidth of the second data line DL1 through DLm overlapped with theauxiliary power source line 212 becomes larger as it goes from the edgeportions of the auxiliary power source line 212 to the center portionthereof. In other words, the widths of the second data lines DL1 throughDLm are set as follows: W1<W2<W3<W4<W5 . . . . Therefore, the seconddata lines DL1 through DLm are set to have approximately equal capacityregardless of position. As the data capacitors Cdata are set to haveapproximately equal capacity, the pixel portion 130 can display an imagewith uniform brightness.

FIG. 9 is an enlarged view showing a second embodiment of “A” shown inFIG. 7.

Referring to FIG. 9, the auxiliary power source line 212 according toanother embodiment is sized so that the areas in which the second datalines DL overlap the auxiliary power source lines 212 are approximatelyequal to each other regardless of the positions of the second data linesDL.

In other words, the auxiliary power source line 212 is set to have thewidth so that the overlapped area between it and the second data linesDL1 and DLm are approximately equal regardless of second data lineposition. Accordingly, as shown in FIG. 9, the width of the auxiliarypower source line 212 is dependent on position, where it is wider in thecenter portion than in the outer portions.

The center width W2 of the auxiliary power source line 212 is wider thanits edge width W1. Therefore, the overlapped areas between the seconddata liens DL1 through DLm and the auxiliary power source lines 212 areset to be equal to each other regardless of position. As a result, thedata capacitors Cdata formed on the second data lines DL1 through DLmare set to have approximately equal capacitance, thereby allowing theorganic light emitting diodes OLED to emit uniform light.

FIG. 10 is an enlarged view showing a third embodiment of “A” shown inFIG. 7.

Referring to FIG. 10, at least one of the second data line DL accordingto one embodiment is set to have bending portions 212 a, 212 b, 212 c,thereby making the areas in which the second data lines DL areoverlapped with the auxiliary power source. lines 212 be approximatelyequal to each other regardless of the positions of the second data linesDL.

Here, the bending portions 212 a, 212 b, 212 c, . . . are formed byzigzag bending the second data line DL, wherein the length bendingportions 212 a, 212 b, 212 c, . . . is dependent on position. Thelengths are shorter at the edge portions of the auxiliary power sourceline 212 than at the center portions thereof. As a result, the lengthsof the second data lines DL1 through DLm overlapped with the auxiliarypower source line 212 are set to be approximately equal to each otherregardless of position. Thus, according to one embodiment, the datacapacitors Cdata formed on the second data lines DL1 through DLm are setto have approximately equal capacitance, thereby allowing the organiclight emitting diodes OLED to emit uniform light.

As described above, an organic light emitting display, in which a datasignal received through one output line is demultiplexed and supplied toa plurality of second data lines. This decreases the number of datasignal output lines and reduces production cost. Further, according toone embodiment, voltages corresponding to the data signals aresequentially stored in data capacitors, and the voltages aresubsequently substantially simultaneously supplied to the pixels. As thevoltages charged in the data capacitors are supplied to the pixels atthe same time, the pixels display an image with uniform brightness.Further, according to one embodiment, a scan period to supply a scansignal is not overlapped with a data period to supply a data signal. Inthis manner the image may be stably displayed. Further, according toanother embodiment, overlapped areas between an auxiliary power sourceline and a second data line are set to be equal to each other, so thatdata capacitors formed on second data lines are approximate equal toeach other in capacitance.

While the above description has pointed out novel features of theinvention as applied to various embodiments, the skilled person willunderstand that various omissions, substitutions, and changes in theform and details of the device or process illustrated may be madewithout departing from the scope of the invention. Therefore, the scopeof the invention is defined by the appended claims rather than by theforegoing description. All variations coming within the meaning andrange of equivalency of the claims are embraced within their scope.

1. An organic light emitting display comprising: a scan driverconfigured to supply scan signals to a plurality of scan lines; a datadriver configured to supply data signals to a plurality of output lines;a plurality of demultiplexers, each configured to selectively supply thedata signals from a single output line to a plurality of data lines; apixel portion comprising a plurality of pixels, the pixel portion beingconnected to the scan lines, the data lines, and a plurality of pixelpower source lines; a first power source line connected to the pixelpower source lines at a first end of each of the pixel power sourcelines; and a plurality of capacitors, wherein each of the capacitors isconfigured to store a charge corresponding to the data signal on acorresponding data line, wherein an auxiliary power source line isplaced between the pixel portion and the data driver and is connected tothe pixel power source lines at a second end of each of the pixel powersource lines, wherein a first of the capacitors has a first width and afirst capacitance, and the first capacitor is formed by a first dataline having the first width and the auxiliary power source line, and asecond of the capacitors has a second width and a second capacitance,and the second capacitor is formed by a second data line having thesecond width and the auxiliary power source line, and wherein the firstand second widths are different and the first and second capacitancesare substantially equal, and wherein the scan driver supplies the scansignals during a first period defined in one horizontal period, and thedata driver supplies the data signals to the plurality of output linesduring a second period defined in the one horizontal period, wherein thefirst and second periods do not overlap.
 2. The organic light emittingdisplay according to claim 1, wherein the width of a data line at anedge portion of the auxiliary power source line is less than the widthof a data line at a center portion of the auxiliary power source line.3. The organic light emitting display according to claim 1, wherein eachdemultiplexer comprises a plurality of transistors, each connected to aseparate data line.
 4. The organic light emitting display according toclaim 3, wherein the plurality of transistors are configured to beturned on in sequence to sequentially supply the data signals to each ofthe separate different data lines, and the capacitors associated withthe corresponding separate data lines are configured to sequentiallystore charge according to the data signals on the corresponding separatedata lines.
 5. The organic light emitting display according to claim 4,wherein a voltage stored on a capacitor is supplied to a pixel duringthe first period.
 6. An organic light emitting display comprising: ascan driver configured to supply scan signals to a plurality of scanlines; a data driver configured to supply the data signals to aplurality of output lines; a plurality of demultiplexers, eachconfigured to selectively supply data signals from a single output lineto a plurality of data lines; a pixel portion comprising a plurality ofpixels, the pixel portion being connected to the scan lines, the datalines, and a plurality of pixel power source lines; a first power sourceline connected to the pixel power source lines at a first end of each ofthe pixel power source lines; and a plurality of capacitors, whereineach of the capacitors is configured to store a charge corresponding tothe data signal on a corresponding data line, wherein an auxiliary powersource line is placed between the pixel portion and the data driver andis connected to the pixel power source lines at a second end of each ofthe pixel power source lines, wherein a first of the capacitors has afirst width and a first capacitance, and the first capacitor is formedby a first data line having the first width and the auxiliary powersource line, and a second of the capacitors has a second width and asecond capacitance, and the second capacitor is formed by a second dataline having the second width and the auxiliary power source line, andwherein the first and second widths are different and the first andsecond capacitances are substantially equal, and wherein the auxiliarypower source line has a center portion wider than an edge portion, andwherein the scan driver supplies the scan signals during a first perioddefined in one horizontal period, and the data driver supplies the datasignals to the plurality of output lines during a second period definedin the one horizontal period, wherein the first and second periods donot overlap.
 7. The organic light emitting display according to claim 6,wherein the width of the auxiliary power source line is narrower at anedge portion than at a center portion.
 8. The organic light emittingdisplay according to claim 6, wherein each demultiplexer comprises aplurality of transistors, each connected to a separate data line.
 9. Theorganic light emitting display according to claim 8, wherein theplurality of transistors are configured to be turned on in sequence soas to sequentially supply the data signals to each of the separatedifferent data lines, and the capacitors associated with thecorresponding separate data lines are configured to sequentially storecharge according to the data signals on the corresponding separate datalines.
 10. The organic light emitting display according to claim 9,wherein a voltage stored on a capacitor is supplied to a pixel duringthe first period.
 11. An organic light emitting display comprising: ascan driver configured to supply scan signals to a plurality of scanlines; a data driver configured to supply the data signals to aplurality of output lines; a plurality of demultiplexers, eachconfigured to selectively supply data signals from a single output lineto a plurality of data lines; a pixel portion comprising a plurality ofpixels, the pixel portion being connected to the scan lines, the datalines, and a plurality of pixel power source lines; a first power sourceline connected to the pixel power source lines at a first end of each ofthe pixel power source lines; and a plurality of capacitors, whereineach of the capacitors is configured to store a charge corresponding tothe data signal on a corresponding data line, wherein an auxiliary powersource line is placed between the pixel portion and the data driver andis connected to the pixel power source lines at a second end of each ofthe pixel power source lines, wherein a first of the capacitors has afirst width and a first capacitance, and the first capacitor is formedby a first data line having the first width and the auxiliary powersource line, and a second of the capacitors has a second width and asecond capacitance, and the second capacitor is formed by a second dataline having the second width and the auxiliary power source line, andwherein the first and second widths are different and the first andsecond capacitances are substantially equal, and each of the first andsecond data lines has a bend, and wherein the scan driver supplies thescan signals during a first period defined in one horizontal period, andthe data driver supplies the data signals to the plurality of outputlines during a second period defined in the one horizontal period,wherein the first and second periods do not overlap.
 12. The organiclight emitting display according to claim 11, wherein a length of one ofthe data lines at an edge portion of the auxiliary power line than isless than a length of another one of the data lines at a center portionof the auxiliary power line.
 13. The organic light emitting displayaccording to claim 11, wherein each demultiplexer comprises a pluralityof transistors, each connected to a separate data line.
 14. The organiclight emitting display according to claim 13, wherein the plurality oftransistors are configured to be turned on in sequence so as tosequentially supply the data signals to each of the separate differentdata lines, and the capacitors associated with the correspondingseparate data lines are configured to sequentially store chargeaccording to the data signals on the corresponding separate data lines.15. The organic light emitting display according to claim 14, wherein avoltage stored on a capacitor is supplied to a pixel during the firstperiod.
 16. An organic light emitting display comprising: a scan driverconfigured to supply scan signals to a plurality of scan lines; a datadriver configured to supply data signals to a plurality of output lines;a plurality of demultiplexers, each configured to selectively supply thedata signals from a single output line to a plurality of data lines; apixel portion comprising a plurality of pixels, the pixel portion beingconnected to the scan lines, the data lines, and pixel power sourcelines; a first power source line connected to the pixel power sourcelines at a first end of each of the pixel power source lines; aplurality of capacitors, wherein each of the capacitors is configured tostore a charge corresponding to the data signal on a corresponding dataline, wherein an auxiliary power source line is placed between the pixelportion and the data driver and is connected to the pixel power sourcelines at a second end of each of the pixel power source lines, wherein afirst of the capacitors has a first width and a first capacitance, andthe first capacitor is formed by a first data line having the firstwidth and the auxiliary power source line, and a second of thecapacitors has a second width and a second capacitance, and the secondcapacitor is formed by a second data line having the second width andthe auxiliary power source line, and wherein the first and second widthsare different and the first and second capacitances are substantiallyequal, and each of the first and second data lines has a bend, andwherein a length of one of the two data lines at an edge portion of theauxiliary power line than is less than a length of another one of thedata lines at a center portion of the auxiliary power line, and thesurface area of each of the plurality of capacitors is substantiallyequal to the surface area of each of the other capacitors.
 17. Theorganic light emitting display according to claim 16, wherein the widthof a data line at an edge portion of the auxiliary power source line isless than the width of a data line at a center portion of the auxiliarypower source line.
 18. The organic light emitting display according toclaim 16, wherein the width of the auxiliary power source line isnarrower at an edge portion than at a center portion.
 19. The organiclight emitting display according to claim 16, wherein the scan driversupplies the scan signals during a first period defined in onehorizontal period, and the data driver supplies the data signals to theplurality of output lines during a second period defined in the onehorizontal period, wherein the first and second periods do not overlap.20. The organic light emitting display according to claim 19, whereineach demultiplexer comprises a plurality of transistors, each connectedto a separate data line.
 21. The organic light emitting displayaccording to claim 20, wherein the plurality of transistors areconfigured to be turned on in sequence to sequentially supply the datasignals to each of the separate different data lines, and the capacitorsassociated with the corresponding separate data lines are configured tosequentially store charge according to the data signals on thecorresponding separate data lines.
 22. The organic light emittingdisplay according to claim 21, wherein a voltage stored on a capacitoris supplied to a pixel during the first period.